Hi, we're booked on the 12-night Eastern Mediterranean cruise Rome-Turkey-Greece-Rome on Carnival Freedom from May 10-22. Does anybody know how many formal nights there are?

The cruise brochure and website says there are generally 2 formal nights for 10-17 day cruises, but I want to know for sure. Does anybody here know? I really like to get dressed up for formal nights and want to be sure to take the right number of dresses.
Thanks!
Tess